鸡蛋破损自动检测系统.doc

院
毕业设计(论文)
题目鸡蛋破损自动检测系统
英文题目 Research for automatic detection of detection of eggshell crack

学生姓名
班级
指导教师
专业自动化
二零零六年六月
摘要
在鸡蛋加工过程中,剔除损壳蛋是保证加工质量及节约成本的一道重要工序。目前常用的方法是人工检测法,这种方法不仅操作工作条件差,劳动强度大,而且检测效果不高,因此,探寻科学实用的鸡蛋破损检测技术是一项非常有意义的工作。
本文首先探索鸡蛋破损的声音检测法。好壳蛋和损壳蛋在被其他物体碰撞时,蛋壳会发出不同的声音,好壳蛋蛋壳发出的声音清脆,而损壳蛋蛋壳发出的声音沙哑,沉闷。利用这一特点,构建了拾音器—声卡—计算机检测系统,试验研究采集敲击鸡蛋的声音信号,再将敲击鸡蛋的模拟信号转换成能被计算机处理的数字信号,然后对敲击鸡蛋的声音信号进行频谱分析找出区分损壳蛋与好壳蛋的显著性因子,依据这些影响因子,运用Bayes判别原理,分别建立好壳蛋与损壳蛋的判别模型,并依据判别模型判断鸡蛋蛋壳是否破损。运用这种检测方法能够判别鸡蛋蛋壳是否破损。
其次,在软件设计方面,本文运用Visual C++编制检测试验程序采集数据,从而设计出鸡蛋破损检测判别模型。依据此研究方法和模型,运用Visual C++编制出基于Windows系统的鸡蛋破损声音检测程序,该程序可以对敲击鸡蛋蛋壳发出的声音信号进行采集、分析处理并判别出鸡蛋蛋壳是否破损。
最后,在硬件设计方面,本研究包括两个方面的工作,一是自动敲击装置的设计,它是由555芯片和一些电子元件构成的多谐振荡电路部分以及与其配套的机械装置部分构成,它能够对鸡蛋自动连续地敲击,并且能够灵活改变敲击的频率和力度。
关键词
破损检测; 自动敲击装置; 声音采集
ABSTRACT
Getting rid of cracked eggshells is an important procedure for guaranteeing quality of processing chicken eggs and saving cost . Detecting chicken eggs by hand not only is badness for it’s working conditions and laboring intension, but also the efficiency is very low . So finding a scientific, applicable and fast detecting method for removing cracked eggshells is very urgent
In this paper, first, we should explore an acoustic impulse method to detect chicken sound is different between normal chicken eggshells and cracked chicken eggshells when being knocked by stiffer materials; the sound of normal eggshells is very silvery and sonorous, while the sound of cracked eggshells is very toneless and tedious. In the established microphone-sound puter detecting system we carried out experiments, first collected the sound signals of chicken eggshells by the microphone, then converted analog signals into digital signals, and then we could make frequency chart for the sound signal by puter, after this we could find out remarkable factors that are affected to distinguish cracked eggshells and normal eggshells, then we made use of “Bayes” discriminance according to these influence